When entrusted with creating a reality model of the second-holiest city in Islam, Ala Abdulhadi & Khalifa Hawas Consulting Engineering Company (AHCEC) turned to an innovative and interoperable digital solution from Bentley Systems, a US design and construction software development company.
Saudi Arabia intends to increase the number of the annual visitors it can accommodate from eight million to 30 million by 2030, which involves a massive redevelopment of the holy cities of Makkah and Madinah. In Madinah, the kingdom aims to build museums and plan routes to historical, culture, and tourist sites and therefore has appointed AHCEC to create the plan, which would include expanding transportation systems and hospitality facilities while preserving historical sites.
AHCEC worked with the Madinah Development Authority to create strategic execution plans for the project. For example, the city wanted to implement reality modelling practices to help plan the development of the 55-sq-km historical area of the city, allowing the team to gather all the proper resources and streamline the project timeline. This model would be used to create a digital twin for the central part of the city.
AHCEC was also asked to help conduct mobile mapping for the 700-sq-km road network, which includes 7,900 km of roads. The team needed to build a comprehensive application that contained 3D mobile mapping and reality mesh data to support the urban planning team. With this large area to cover and the deadline shortened from two years to one, AHCEC turned to Bentley’s innovative digital solutions such as ContextCapture and Orbit.
Conducting Surveying and Mapping
To begin, the project team captured LiDAR data to create a hybrid model that also included unmanned aerial vehicle (UAV) data. Other team members drove through the streets to capture data for the model. AHCEC divided the city into 2.25-hectare cells and used six UAVs in the field. The team established 1,038 control points around the city, which allowed them to ensure accuracy and finish data capture in 85 days with 7,033 UAV flights.
Using ContextCapture, the project team processed nearly 750,000 images, about 13.7 terapixels, to create a realistic 3D model of the city. AHCEC also used Orbit, Bentley’s 3D mapping solution to manage the large amounts of mobile mapping data. Orbit helped effectively manage and feature extract content, as well as publish mobile mapping data. The application was able to manage and extract the large amounts of drone data and create panoramic images for the model. The interoperability of the applications also allowed the model to be exported in web-ready formats for easier approvals from the government and other stakeholders.
By using ContextCapture and Orbit, AHCEC was able to document each historical spot in the city using realistic and detailed models. These models were used to help develop new roads through the city, superimposing other models on the reality model so designers and engineers could see everything accurately and clearly laid out.
The model captured every feature of the highly congested area, including trees and the texture of the buildings. Even narrow, dark alleys were modelled in great detail with a combination of laser scanning and photogrammetry. The team also implemented data from existing point clouds.
The model provided a single location where the multidiscipline site planning and engineering teams could find information that they needed. It is now easy to share the models with other departments, as well as visualise and measure without having much experience in 2D or 3D modelling. Lastly, the team conducted a feasibility study for a 3-km walkway between two important mosques, as well as shading analyses to allow for maximum walking comfort between the mosques and surrounding facilities.
Foundation for Future Projects
Reality modelling provided the team with a reliable survey technique that minimised modelling time and costs while streamlining decision-making and visualisation. AHCEC’s reality model helped the team complete the project 15 months ahead of schedule while still creating a design that facilitates pilgrim access to Madinah.
Using ContextCapture and Orbit, the project team completed the objective in nine months, saving over a year in surveying time and more than SR42 million. The team captured more than 750,000 images, modelled 41,672 buildings, and surveyed more than 7,000 km of roads in high definition. This project was the first of its scale in Saudi Arabia to use consumer UAVs in such a short timeframe.
Moving forward, the team will use Bentley’s iTwin Services to create a digital twin. AHCEC plans to collect information from utilities, including environmental sensors, to add to the reality model. The team plans to implement AssetWise and ProjectWise, creating a single source for all project information that can be contained in the reality model.